Various foodstuffs, packed, moulded or cold cuts are prepared using a cooking stage, which is usually carried out according to two different systems: by immersion in a hot liquid, generally water held in a boiler; or through the action of steam inside a cooking vessel. Each of these two methods has both advantages and disadvantages, which are examined below.
Cooking by immersion in hot water has the advantage of presenting excellent thermal interchange and heat transmission, which is translated into shorter cooking times. It also provides a good uniformity of temperature inside the boiler, which facilitates regulation. Its main disadvantage is inconvenient loading, since this type of boiler opens at the top. This thus requires, for example, bridge cranes to raise the batch of food and lower it into the boilers forming layers. This will require a building with a considerable ceiling height and, the larger the batches handled in order to reduce loading and unloading times, the higher the required ceiling height.
ARMOR-INOX, S.A. patent EP-A-0334782 described a cooking installation for cooking foodstuffs by immersion in a hot liquid, followed by at least one immersion in a cold liquid in order to remove the cooled products. The installation consists of a series of boilers, each with an opening at the top for loading and unloading, together with an inlet and outlet for the liquids, the means of heating in order to obtain a hot liquid stored in another tank and a connection to the mains water supply. The hot and cold liquids, together with the running water are distributed by means of piping to the respective boiler inlets in order to fill them and to collect the liquids from the corresponding outlets so that the boilers can be emptied and the liquids returned to their respective tanks. The installation includes an emptying pump for each boiler, which permits the independent filling or emptying of each boiler. U.S. Pat. No. 6,085,639, also belonging to ARMOR-INOX, S.A. describes an installation that is very similar to the previous one, in which the independent filling and emptying operations for each boiler are carried out via the same inlet/outlet pipe by means of a reversible pump. Neither of these two cited patents describes access to the boilers from a side opening that can be hermetically sealed.
The cooking via steam inside a cabin has the advantage of being able to employ a side access for loading and unloading the cabins, which will eliminate the requirement for high ceiling heights because the batches of food are placed on trolleys, which then enter the cooking cabins. In addition, the use of steam involves low energy costs and simple maintenance. However, this type of cooking has the disadvantage of inferior interchange and transmission of heat with respect to immersion in hot liquid, which will therefore require longer cooking times. Moreover, obtaining a uniform temperature inside the cabin is more difficult and requires very precise steam distribution to prevent irregular cooking of the pieces in the same batch.
The objective of this invention is to provide an installation for cooking food that benefits from the advantages of both the systems described above but, at the same time, avoids the associated main disadvantages of each.